Broadcasts (Zenitel Connect Pro)

A Broadcast call is a one-way distribution of audio to a number of recipients in parallel. A user can dial a Broadcast call number to send live audio to receiving devices, for example for public announcement. It is also possible to dispatch a pre-recodorded Audio Message to a Broadcast group.

Configuration

Create Broadcast calls

From the Zenitel Connect Pro web interface, navigate to Features > Broadcasts. By default there are no broadcast calls defined. To add a new broadcast , click and define a directory number, name, priority and call time out. Click to accept the entry.

A system configured with 4 broadcast groups

Directory Number: Any number (Recommended numbers are 840 - 859)
Name: The SIP display name
Priority: 1-250. Default is 70
Call Timeout: Max duration of call before automatic hang-up, 0 means no timeout
Members: A list of receiving devices
Multicast Address is a read-only value, visible only when there is at least one ITSV video phone or Generic SIP device included as member.

ITSV devices can be added as member of a broadcast call, and receive broadcast call audio. However the full set of features described below is only available for native Zenitel devices as receivers.

The Answer Timeout in the Devices and Connections > Global Parameters setting controls how long a Broadcast call will be queued on busy.

Broadcast membership

Select the broadcast group by clicking on the radio button to the left.
Select members from the list of available devices in the list to the left.
Click to move selected devices to the section Members. Use the to remove a device from the group.

Adding members to a broadcast group

Functions

Live broadcast

To do announcement from an intercom device:

Dial the broadcast number
A chime signal is heard in all member devices
As soon as the chime signal is finished the microphone will open (no need to press any PTT button), and the operator can speak
End the broadcast by pressing the C-key or by replacing the handset

To trigger announcement via Zenitel Link:

Link API: POST /api/calls “from_dirno”: <source device> “to_dirno”: <Broadcast call>

Dispatch pre-recorded message

From an intercom device: *9*<message>*<broadcast>#
From Zenitel Link: Link API: POST /api/calls “from_dirno”: <message> “to_dirno”: <Broadcast call>

For more details, see Audio Messages

Priorities and Permissions

Broadcast call setup priority

Before setting up a Broadcast call, Zenitel Connect Pro will check if the broadcast overlaps with any other active broadcast calls.

If there are conflicting calls, the Broadcast call will be queued with busy tone to caller.
If all conflicting calls have lower priority (a higher priority value 1 -250), the conflicting calls are cancelled, and the new call is connected.
Otherwise the call will stay in queue, and will be connected if the conflicting call hangs up. Max duration in queue is controlled by global “Answer Timeout” setting.

Offline member devices do not block Broadcast call setup.

When the Broadcast call is connected, Zenitel Connect Pro will play a “ding-dong” chime (hard coded) to all parties as attention signal.

The callers microphone is connected to the Broadcast call immediately after the attention signal. There is no support for PTT (Press To Talk).

Broadcast call received while in a Regular call

The Broadcast call priority controls the interaction between Broadcast audio and regular call audio.

Priority 1-20 (Emergency): Regular call audio is muted. Only broadcast audio is played. Volume and handset override is activated.
Priority 21-40 (High): The Broadcast audio is mixed with the regular call
Priority 41-250 (Normal / Low): The Broadcast audio is not played

When using the default broadcast priority (70) the intercom device will not play broadcast audio while active in a regular call.

Permissions

By default all users can initiate a broadcast. Often there is a need to set access restrictions, and allow selected users only to initiate broadcast. To configure restrictions navigate to Devices and Connections > Call Services and cofigure restrictions on "Broadcast numbers".

Networking

Broadcast call audio is distributed on multicast, 239.192.0.0/14 IPv4 (Organization Local Scope). If there are devices on different IP subnets than the Zenitel Connect Pro, intervening routers have to be configured for multicast.

UDP ports between 61080 and 61700 are used on devices for Broadcast call audio reception.

Characteristics

Parameter	Value	Comment
Max receivers in broadcast call	-	No limit, as many as supported devices.
Max broadcast call numbers including ITSV or Generic SIP devices	50	Limited by multicast address/port range
Max simultaneous broadcast calls	250	Limited by multicast address/port range
Max broadcast memberships for ITSV	10	Limited by the maximum number of multicast addresses the ITSV supports
Max membership for Generic SIP devices	No specific limit	Depends on the maximum number of multicast addresses the SIP device supports

Fault finding and limitations

If it takes several seconds before the chime is heard in the calling device, there is a problem with setting up the call to all online native device members.

Zenitel Connect Pro sends requests to all online native member devices in a tight loop, and then collects responses from the devices.

If a device does not receive audio there is a 2 second timeout in the device before sending a response
When all devices have responded, the broadcast call starts
If some devices are not responding at all there is a 3 second timeout in the server, before starting the broadcast call

Offline devices are skipped in the setup, and will not contribute to delay.

Check the System log for device_status message with status_type: broadcast_call.

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